Cartridge for applying varying amounts of tissue compression

ABSTRACT

A surgical stapling apparatus includes a staple cartridge and an anvil member. The staple cartridge includes a plurality of surgical fasteners disposed in rows of retention slots. The staple cartridge may have an annular or linear configuration of retention slots. The tissue contacting surface of the staple cartridge may be tapered or stepped. The anvil member has a tissue contacting surface that includes a number of pockets arranged for substantially aligning with the retention slots. In addition, the tissue contacting surface of the anvil member may complement the tissue contacting surface of the staple cartridge.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.13/228,017 filed Sep. 8, 2011, now U.S. Pat. No. 8,256,655, which is acontinuation of U.S. application Ser. No. 12/422,501 filed Apr. 13,2009, now U.S. Pat. No. 8,028,884, which claims benefit of applicationNo. 61/046,883 filed on Apr. 22, 2008, and the disclosures of each ofthe above-identified applications are hereby incorporated by referencein their entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to surgical fastener apparatus andsurgical fastener cartridges, and more particularly, to apparatus andcartridges for applying varying amounts of tissue compression.

2. Background of Related Art

Many varieties of surgical fastening apparatus are known in the art,some of which are specifically adapted for use in various surgicalprocedures including, but not limited to, end-to-end anastomosis,circular end-to-end anastomosis, open gastrointestinal anastomosis,endoscopic gastrointestinal anastomosis, and transverse anastomosis.Suitable examples of apparatus which may be used during the course theseprocedures can be seen in U.S. Pat. Nos. 5,915,616; 6,202,914;5,865,361; and 5,964,394.

In general, a surgical fastening apparatus will include an anvil that isapproximated relative to a fastener cartridge during use. The anvilincludes depressions that are aligned with, and/or are in registrationwith slots defined in the cartridge, through which the fasteners willemerge, to effectuate formation. The fastener cartridge typically hasone or more rows of fasteners disposed laterally or radially of achannel that is configured to accommodate a knife, or other such cuttingelement, such that tissue can be simultaneously cut and joined together.Depending upon the particular surgical fastening apparatus, the rows offasteners may be arranged in a linear or non-linear, e.g. circular,semi-circular, or otherwise arcuate configuration.

Various types of surgical fasteners are well known in the art, includingbut not limited to unitary fasteners and two-part fasteners. Unitaryfasteners generally include a pair of legs adapted to penetrate tissueand connected by a backspan from which they extend. In use, the unitaryfasteners are formed by driving them into the depressions formed on theanvil, and subsequent to formation, the unitary fasteners have a “B”shaped configuration. Typically, the two-part fastener includes legsthat are barbed and connected by a backspan which are engaged and lockedinto a separate retainer piece that is usually located in the anvil. Inuse, the two-part fastener is pressed into the tissue so that the barbspenetrate the tissue and emerge from the other side where they are thenlocked into the retainer piece. The retainers prevent the two-partfastener from dislodging from the tissue. The two-part fasteners are notintended to be unlocked or removable. For this reason, they aregenerally made of a bioabsorbable material.

During each of the aforementioned surgical procedures, the tissue isinitially gripped or clamped such that individual fasteners can beejected from the cartridge, through the slots, and forced through theclamped tissue.

A common concern in each of these procedures is hemostasis, or the rateat which bleeding of the target tissue is stopped. It is commonly knownthat by increasing the amount of pressure applied to a wound, the flowof blood can be limited, thereby decreasing the time necessary toachieve hemostasis. To this end, conventional surgical fasteningapparatus generally apply two or more rows of fasteners about thecut-line to compress the surrounding tissue in an effort to stop anybleeding and to join the cut tissue together. Each of the fasteners willgenerally apply a compressive force to the tissue sufficient toeffectuate hemostasis, however, if too much pressure is applied, thiscan result in a needless reduction in blood flow to the tissuesurrounding the cut-line. Accordingly, the joining of tissue together inthis manner may result in an elevated level of necrosis, a slower rateof healing, and/or a greater recovery period.

Consequently, it would be advantageous to provide a surgical fasteningapparatus capable of limiting the flow of blood in the tissueimmediately adjacent the cut tissue to effectuate hemostasis and woundclosure, while maximizing blood flow in the surrounding tissue tofacilitate healing.

Additionally, when tissue is clamped and compressed between the anviland cartridge, some of the fluid of the tissue is squeezed out inpreparation for receiving the fasteners. It would be advantageous toprovide staples which could better accommodate different tissuethicknesses.

SUMMARY

The present disclosure is directed towards surgical stapling instrumentsconfigured to effectuate an improved balance between the anastomoticstrength and the degree of hemostasis at the tissue interface. Inparticular, embodiments of the present disclosure include surgicalfasteners of different sizes. Further still, the distance between ananvil member and a staple cartridge (i.e. the gap) varies along alongitudinal axis of the staple cartridge. Combining the different sizesof surgical fasteners with the varying gap between the anvil member andthe staple cartridge improves the anastomotic strength and the degree ofhemostasis at the tissue interface.

An end effector is disclosed herein for a surgical instrument includingan operative tool having a width and a length, wherein the operativetool includes an anvil and a cartridge disposed along the length of theoperative tool and defining a gap therebetween. The gap defined betweenthe anvil and the cartridge has at least two different sizes between afirst and a second end of the length of the operative tool. The gap maybe substantially constant size along the width of the operative tool.The anvil and the cartridge are adapted to grasp tissue therebetweensuch that a pressure corresponding to the size of the gap between theanvil and the cartridge is applied to the tissue. The value of thepressure between the first end and the second end is not constant andmay define a pressure gradient.

According to one aspect of the disclosure, the surgical staplinginstrument includes a first structure defining an anvil memberoperatively associated therewith, and a second structure defining astaple cartridge operatively associated therewith. The staple cartridgehas a tissue contacting surface with a stepped profile. The tissuecontacting surface of the staple cartridge also includes a plurality ofretention slots formed therein for retaining a surgical fastener. Duringoperation of the surgical stapling instrument, the anvil member and thestaple cartridge can be approximated relative to one another. Thesurgical fasteners may include a backspan and a pair of legs that have alength corresponding to the size of the gap between the anvil and thecartridge.

In one embodiment, the staple cartridge includes a first section havinga first tissue contacting surface that defines a first gap between thefirst tissue contacting surface and the tissue contacting surface of theanvil member. In addition, the staple cartridge includes a secondsection and a third section having second and third tissue contactingsurfaces that define second and third gaps between the second and thirdtissue contacting surfaces and the tissue contacting surface of theanvil member. The first gap may be different from the second gap and/orthe third gap such that the tissue contacting surfaces form a steppedprofile.

The cartridge may also include a plurality of receiving sectionsadjacently positioned along an axis of the cartridge. Each receivingsection is adapted to receive a removable tissue contacting sectiontherein. Each of the removable tissue contacting sections has a tissuecontacting surface. A clinician may position the removable contactingsections within the receiving sections and position the sectionsadjacent to one another to adjust the size of the gap between the tissuecontacting surfaces and the anvil. By adjusting the size of the gap, thepressure applied to tissue when grasped between the anvil and thecartridge may be adjusted.

The presently disclosed surgical stapling instruments, together withattendant advantages, will be more clearly illustrated below by thedescription of the drawings and the detailed description of theembodiments. Other objects and features of the present disclosure willbecome apparent from consideration of the following description taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the presently disclosed surgical stapling apparatus aredescribed herein with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective view of a surgical stapling instrument inaccordance with an embodiment of the present disclosure;

FIG. 2 is a perspective view of a surgical stapling instrument inaccordance with an alternate embodiment of the present disclosure;

FIG. 3 is a perspective view of a surgical stapling instrument inaccordance with a further embodiment of the present disclosure;

FIG. 4 is a perspective view of an end effector in accordance with anembodiment of the present disclosure;

FIG. 5 is a perspective view of an end effector in accordance with analternate embodiment of the present disclosure; and

FIG. 6 is a side cross-sectional view of the resulting tissue interfacefollowing the firing of the surgical stapling instrument of FIGS. 1-3.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed surgical stapling instrumentswill now be described in detail with reference to the drawing figureswherein like reference numerals identify similar or identical elements.In the drawings and in the description which follows, the term“proximal”, as is traditional, will refer to the end of the surgicalstapling instrument which is closest to the operator while the term“distal” will refer to the end of the device which is furthest from theoperator.

Turning now to FIG. 1, a surgical stapling instrument, of thegastro-intestinal anastomosis type for performing surgical anastomoticstapling, in accordance with an embodiment of the disclosure, isgenerally designated as 100. Surgical stapling instrument 100 includes afirst handle 102 having a jaw 103 defining a staple cartridge receivingsection extending from a distal end thereof, a staple cartridge 104receivable in jaw 103, a second handle 106 having a jaw 105 defining ananvil member receiving section extending from a distal end thereof, andan anvil member 108 operatively associated with jaw 105. First andsecond handles 102, 106 are configured such that staple cartridge 104 issubstantially aligned with anvil member 108.

In operation, surgical stapling instrument 100 is fired similarly to andin accordance with other known surgical stapling instruments. An exampleof a surgical stapling apparatus and methods for its use are isdisclosed in U.S. Pat. No. 6,202,914, currently assigned to TycoHealthcare Group LP, the entire contents of which is hereby incorporatedherein by reference. The cartridge 104 defines a plurality of slots anda tissue contacting surface. A plurality of surgical fasteners isdisposed in the slots of the cartridge 104. Adjacent to the surgicalfasteners are ejectors or pushers. By moving the first and secondhandles 102, 106 towards each other, an actuator mounted within thecartridge 104 translates therein to transmit a driving force to theejectors or pushers to thereby eject the surgical fasteners from theslots and driven against an staple forming surface of the anvil member108. Sequential firing of the surgical fasteners may continue until allthe staples once housed in the cartridge 104 are ejected.

Turning now to FIG. 2, a surgical stapling instrument, of thelaparoscopic type for performing surgical anastomotic stapling, inaccordance with another embodiment of the disclosure, is generallydesignated as 200. Surgical stapling instrument 200 includes a handleassembly 202, an operative tool 206, and an elongated shaft 204 forinterconnecting operative tool 206 to handle assembly 202. In general,operative tool 206 is designed to clamp over and then to staple anddivide tissue held therein. Accordingly, as seen in FIG. 2, operativetool 206 is a pair of opposed jaws including an anvil member 208 and astaple cartridge 210 pivotally coupled to one another.

In operation, surgical stapling instrument 200 is fired similarly to andin accordance with other known surgical stapling instruments. For adetailed discussion of the approximation and firing of surgical staplinginstrument 200, reference is made to commonly assigned U.S. Pat. No.5,865,361, currently assigned to Tyco Healthcare Group LP, the entirecontents of which is hereby incorporated herein by reference. The handleassembly 202 includes a housing 203, which includes stationary handlemember 205. A movable handle 207 is pivotably supported within thehousing 203 and is biased away from the stationary handle member 205.Movement of the movable handle 207 in the direction of the stationaryhandle member 205 urges the anvil member 208 towards the staplecartridge 210 such that the anvil member 208 and the staple cartridge210 are in close cooperative alignment. Subsequently, continued movementof movable handle 207 imparts a driving force to an actuation shaftwithin the housing 202 causing it to advance linearly in a distaldirection. The anvil member 208 and the staple cartridge 210 are movedcloser relative to each other and a force is transmitted to the ejectorsor pushers positioned adjacent to surgical fasteners disposed withinslots of the staple cartridge 210 to thereby eject the surgicalfasteners and to drive the surgical fasteners against a staple formingsurface of the anvil member 208.

Turning now to FIG. 3, a surgical stapling instrument 300, of thetransverse anastomosis type for performing surgical anastomoticstapling, in accordance with yet another embodiment of the disclosure,is generally designated as 300. Surgical stapling instrument 300includes a handle assembly 302, a barrel 304 extending from handleassembly 302, and an arm 306 extending from the distal end of barrel304. Surgical stapling instrument 300 further includes an anvil member308 orthogonally affixed to a distal end of arm 306 and a staplecartridge receiver 340 operatively coupled to the distal end of barrel304 for holding a disposable staple cartridge 310 thereon. The anvilmember 308 and the staple cartridge 310 define an operative tool 316.

In operation, surgical stapling instrument 300 is fired similarly to andin accordance with other known surgical stapling instruments. For adetailed discussion of the approximation and firing of surgical staplinginstrument 300, reference is made to commonly assigned U.S. Pat. No.5,964,394, currently assigned to Tyco Healthcare Group LP, the entirecontents of which is incorporated herein by reference. The handleassembly 302 includes a housing 305, which includes a stationary handlemember 307. A movable handle 303 is pivotably supported within thehousing 305 and is biased away from the stationary handle member 307.Movement of the movable handle member 303 in the direction of thestationary handle member 307 imparts a driving force to an actuationshaft within the housing 305 which in turn imparts a force to a pusherbar within the staple cartridge 310 to thereby eject fasteners disposedwithin slots of the staple cartridge 10 and to drive the surgicalfasteners against a staple forming surface of the anvil member 308.

Referring now to FIG. 4, the operative tool 206 is illustrated with theanvil member 208 in an open position. The anvil member 208 has a planartissue contacting surface that faces towards the staple cartridge 210.Additionally, the anvil member 208 has a tissue contacting surface thatincludes a plurality of depressions or pockets (not shown) that arearranged for cooperating with retention slots 223 of the staplecartridge 210 for forming completed surgical fasteners. Staple cartridge210 includes a first section 210 a, a second section 210 b, and a thirdsection 210 c. In the illustrated embodiment, first section 210 a has afirst height that defines a first gap between the anvil member 208 andfirst tissue contacting surface 212 a. Similarly, second and thirdsections 210 b, 210 c have second and third heights, respectively, thatdefine second and third gaps between the anvil member 208 and tissuecontacting surfaces 212 b, 212 c respectively. As shown in FIG. 4, thesize of the first gap is less than the second gap which is less than thethird gap so that the size of the gap between the anvil member 208 andstaple cartridge 210 increases in the distal direction. Otherarrangements of gaps are envisioned. For example, the most distalportion of the staple cartridge 210 may have the smallest gap.Alternatively, two of the sections may define the same gap with respectto the anvil member 208. Further still, the operative tool 206 mayinclude a channel 230 for accommodating a cutting member (not shown)that travels along the longitudinal axis A-A of the operative tool 206.

Although illustrated as a unitary construction, it is envisioned thateach of the sections 210 a, 210 b, and/or 210 c may be individuallyreplaceable such that the operative tool 206 may be reconfigured andadapted for different surgical procedures. As such, each section 210 a,210 b, and 210 c may be individually installable in the staple cartridge210. In this configuration, the staple cartridge 210 may be reconfiguredby the practitioner just prior to use, thereby providing increasedflexibility of the instrument by allowing the practitioner to rearrangethe stepped configuration of the gaps according to the surgicalprocedure to be performed.

In further embodiments, the anvil member may have a tissue contactingsurface with a height that varies along the longitudinal axis. Theheights of the tissue contacting surfaces of the anvil, the cartridge,or both, vary to accommodate tissue of different thicknesses.

Although the arrangement of the staple cartridge sections are discussedwith respect to the operative tool 206, the above-mentioned arrangementsand configurations are readily adaptable for use with surgical staplingapparatus 100 as well.

Referring now to FIG. 5, a further embodiment of the staple cartridge isdisclosed and generally identified as 310. Staple cartridge 310 isdisposed in a staple cartridge receiver 340 and defines a tissuecontacting surface. Similar to previously discussed staple cartridge210, staple cartridge 310 includes a first section 310 a, a secondsection 310 b, and a third section 310 c. In the illustrated embodiment,first section 310 a has a first height that defines a first gap betweenan anvil member 308 and first tissue contacting surface 312 a.Similarly, second and third sections 310 b, 310 c have second and thirdheights, respectively, that define second and third gaps between theanvil member 308 and tissue contacting surfaces 312 b, 312 crespectively. Other arrangements of gaps are envisioned. For example,the portion of the staple cartridge 310 at one end of the staplecartridge receiver 340 may have the smallest gap. Alternatively, two ofthe sections may define the same gap with respect to the anvil member308. Further still, the operative tool 316 may include a channel 330 forguiding a cutting member (not shown) along the longitudinal axis of theoperative tool 306. Additionally, the anvil member 308 includes aplurality of depressions or pockets (not shown) that are arranged forcooperating with retention slots of 323 of the staple cartridge 310 forforming completed surgical fasteners.

It is contemplated that the operative tool 316 may have an anvil memberwith a tissue contacting surface with a height that varies along thelongitudinal axis of the anvil member defining a stepped configurationsimilar to that of the staple cartridge 310. The stepped configurationof the tissue contacting surface of the anvil member 308 may becomplementary to that of the tissue contacting surface of the staplecartridge 310 and defining a tissue compression gradient along thelongitudinal axis of the operative tool 316. In particular, the steppedconfiguration of the tissue contacting surfaces of the anvil member 308and the staple cartridge 310 vary in tandem. Alternatively, the tissuecontacting surface of the anvil member 308 may have a steppedconfiguration that varies in opposition to the stepped configuration ofthe tissue contacting surface of the staple cartridge 310. Othercombinations of gaps formed between the tissue contacting surfaces ofthe anvil member 308 and the staple cartridge 310 are envisioned. It isfurther contemplated that any of these arrangements are adaptable foruse in operative tool 206.

Although illustrated as a unitary construction, it is envisioned thateach of the sections 310 a, 310 b, and/or 310 c may be individuallyreplaceable such that the operative tool 316 may be reconfigured andadapted for different surgical procedures. As such, each section 310 a,310 b, and 310 c may be individually installable in the staple cartridge310. In this configuration, the staple cartridge 310 may be reconfiguredby the practitioner just prior to use, thereby providing increasedflexibility of the instrument by allowing the practitioner to rearrangethe stepped configuration of the gaps according to the surgicalprocedure to be performed.

Additionally, it is envisioned that the operative tool 206 or staplecartridge 310 may be included in a kit that also includes additionalsections of varying heights that allow the practitioner to install thedesired sections for the procedure to be performed. For instance, thekit may include the operative tool 206 or staple cartridge 310 and aplurality of staple cartridge sections (i.e. 210 a, 210 b, 210 c or 310a, 310 b, 310 c). Thus, the practitioner may select and install thedesired sections and form the staple cartridge 210 or 310 with aconfiguration suitable for the procedure to be performed. As envisioned,the practitioner may, by way of example only, select and arrange thesections such that the first gap is the largest, the intermediary orsecond gap is less than the first gap, and the third gap is thesmallest. Similarly, the practitioner may select and arrange the staplecartridge sections such that the first and third gaps are identical withthe second gap being different. Other combinations using individuallyselectable staple cartridge sections may be chosen by the practitioner.

Regardless of whether the staple cartridge sections are individuallyselectable or the staple cartridge is supplied as a unitary structure,the operative tool 206 or staple cartridge 310 provides a tissuecompression gradient when tissue is captured between the tissuecontacting surface of the anvil member 208, 308 and the surfaces of thestaple cartridge 210 or 310. Tissue or layers of tissue positionedbetween first tissue contacting surface 212 a, 312 a and the anvilmember 208, 308 is compressed to a first value when the anvil member208, 308 is approximated with the staple cartridge 210, 310. Similarly,tissue or layers of tissue positioned between second and third tissuecontacting surfaces 212 b, 312 b and 212 c, 312 c and the anvil member208, 308 are compressed to respective second and third values when theanvil member 208, 308 is approximated with the staple cartridge 210,310. The first value is greater than the second value which is greaterthan the third value, thereby providing a tissue compression gradientthat decreases from the proximal portion of the operative tool 206towards the distal portion of the operative tool 206 or from a firstregion towards a second region of operative tool 316. As discussedhereinabove, the arrangement of gaps may be altered in view of thesurgical procedure to be performed, thereby allowing the practitioner tovary the tissue compression gradient as needed.

In addition, the operative tool 206, 316 is suitable for proceduresinvolving organs or sections of the patient's body that have thinsections of tissue adjacent thicker sections of tissue, where thevariation in the tissue thickness is along the longitudinal axis of theoperative tool 206, 316. The operative tool 206, 316 is arranged toaccommodate differences in the thickness of the tissue. For example, ina wedge resection of lung tissue using operative tool 206, the tissue atthe distal end of staple cartridge 210 is thicker than tissue at theproximal end of the staple cartridge 210.

Turning now to FIG. 6, a cross-section of the resulting tissueinterface, following the firing of staple cartridge 210, 310, is shown.As seen in FIG. 6, the tissue interface has a stepped profile. Anexample of a staple cartridge having a tapered or stepped profile can beseen in U.S. Pat. No. 7,398,908, the contents of which are herebyincorporated by reference. The distance between an anvil member and astaple cartridge, i.e., a gap, may vary from a centerline of the staplecartridge to an outer edge of the staple cartridge. Surgical fastenersincluding a pair of legs and a backspan have a leg length thatcorresponds to the gap.

Each retention slot 223, 323 is configured and dimensioned to retain astaple or surgical fastener 125 (FIG. 6) therein. Each surgical fastener125 includes a backspan 27 and a pair of depending legs 25. Legs 25 a ofsurgical fasteners 125 a have a first leg length, legs 25 b of surgicalfasteners 125 b have a second leg length, and legs 25 c of surgicalfasteners 125 c have a third leg length. In one embodiment, legs 25 c ofsurgical fasteners 125 c have a leg length of about 2.3 mm, legs 25 b ofsurgical fasteners 125 b have a leg length of about 3.5 mm, and legs 25a of surgical fasteners 125 a have a leg length of about 4.1 mm.

Using this configuration, surgical fasteners 125 a having the shortestleg lengths are deployed in first section 210 a, 310 a (i.e. having thesmallest gap), while surgical fasteners 125 b, 125 c are disposedrespectively in sections 210 b, 310 b and 210 c, 310 c having largergaps. In the illustrated embodiment, layers of tissue T1, T2 are joinedtogether using one of the presently disclosed surgical staplinginstruments 100, 200, 300. The region of the operative tool 206, 316having the smallest gap employs surgical fasteners 125 a and compressingtissue layers T1, T2 by a first predetermined amount for a first tissuepressure. Similarly, the region of the operative tool 206, 316 having alarger gap employs surgical fasteners 125 b, thereby compressing tissuelayers T1, T2 by a second predetermined amount for a second tissuepressure. Finally, the region of the operative tool 206, 316 having thegreatest gap employs surgical fasteners 125 c, thereby compressingtissue layers T1, T2 by a third predetermined amount for a third tissuepressure. The thickness of the tissue in relation to the plurality ofgaps contributes to the values of the plurality of tissue pressures. Aspreviously disclosed, the arrangement of the gaps may be altered eitherduring the manufacturing process or by utilizing discrete sections ofthe staple cartridge for the physician to field modify the operativetool.

By providing tissue contacting surfaces 212 a, 212 b, 21 c or 312 a, 312b, 312 c in a stepped configuration, the anastomotic strength and thedegree of hemostasis at the tissue interface improves when layers ofbody tissue are clamped between anvil member 208,308 and staplecartridge 210, 310. In particular, this arrangement provides gradualtissue loading or compression due to the varying gap defined betweenanvil member 208,308 and staple cartridge 210,310 when they are in theapproximated position (i.e. they are substantially parallel to oneanother), thereby minimizing tissue trauma while maintaining arelatively high degree of hemostasis and anastomotic strength.Embodiments of a surgical stapling instrument can be used to provide avariable pressure gradient (i.e. load profile) to the layers of tissuethat are joined together with the surgical fasteners. Therefore, thelayers of tissue that are located in the region with the smallest gapbetween the anvil member and the staple cartridge are subjected tohigher compressive forces (i.e. loads), as compared to layers of tissuethat are in regions of the surgical stapling instrument having largergaps between the anvil member and the staple cartridge. Since the layersof tissue in the first gap can be compressed more, a smaller sized (i.e.shorter leg lengths, shorter backspans, or both) surgical staple orfastener can be used to mechanically suture (i.e. fasten) the layers oftissue. Further still, providing a gradual compression gradient to thelayers of tissue to be joined, may result in a higher degree ofhemostasis and/or better staple formation.

In contexts where the thickness of the tissue to be stapled or joinedvaries, embodiments of the surgical stapling instrument according to thepresent disclosure can be used to accommodate different thicknesses bydeploying larger sized staples (i.e. longer leg lengths, longerbackspans, or both) in thicker tissue and smaller sized staples (i.e.shorter leg lengths, shorter backspans, or both) in thinner tissue, forbetter staple formation and improved hemostasis.

It will be understood that various modifications may be made to theembodiments of the presently disclosed surgical stapling instruments.Therefore, the above description should not be construed as limiting,but merely as exemplifications of embodiments. Those skilled in the artwill envision other modifications within the scope and spirit of thepresent disclosure.

What is claimed is:
 1. A surgical instrument, comprising: an anvilincluding an anvil tissue contacting surface; and a cartridge adapted toconnect to a jaw member of the surgical instrument including a firstsection having a first cartridge tissue contacting surface and a secondsection having a second cartridge tissue contacting surface, each of thefirst and second cartridge tissue contacting surfaces includingretention slots for the retention of surgical fasteners therein, thefirst section and the second section being removably couplable to thecartridge, wherein the anvil and the cartridge define a first gapbetween the first cartridge tissue contacting surface of the cartridgeand the tissue contacting surface of the anvil and a second gap betweenthe second cartridge tissue contacting surface of the cartridge and thetissue contacting surface of the anvil, the first gap defining a firstdistance between the first cartridge tissue contacting surface of thecartridge and the tissue contacting surface of the anvil, the second gapdefining a second distance between the second cartridge tissuecontacting surface of the cartridge and the tissue contacting surface ofthe anvil, the first distance being different than the second distance,the first gap and the second gap being spaced apart along a longitudinalaxis of the end effector.
 2. The surgical instrument of claim 1, whereinapproximation of the anvil and the cartridge applies pressure to tissuepositioned therebetween.
 3. The surgical instrument of claim 2, whereinapproximation of the anvil and the cartridge and the clamping of tissuetherebetween produces a first value of pressure applied at the firstgap, and a second value of pressure applied at the second gap.
 4. Thesurgical instrument of claim 1, wherein the cartridge includes aplurality of surgical fasteners disposed therein.
 5. The surgicalinstrument of claim 4, wherein each of the first section and the secondsection have a plurality of surgical fasteners disposed therein.
 6. Thesurgical instrument of claim 5, wherein each of the surgical fastenersinclude a backspan and a pair of legs.
 7. The surgical instrument ofclaim 6, wherein the legs of the fasteners of the first section have adifferent length than the legs of the fasteners of the second section.8. The surgical instrument of claim 1, wherein each of the first sectionand the second section are removable and selectively positionable toadjust the size of a gap between each of the first section and thesecond section, and the tissue contacting surface of the anvil.
 9. Thesurgical instrument of claim 1, wherein the first section is disposeddistally of the second section, the first section defining a larger gapwith the tissue contacting surface of the anvil than a gap defined bythe second section and the tissue contacting surface of the anvil.